Combustion chamber



Sept. 14, 1943. E. w. JoRoLEMoN GOMBUSTION CHAMBER Filed llamh 20, 1940 3 Sheets-Sheet l Snnentor 3a/2l i/bfvlezzzozz Sept. 14, 1943. E. w. .JoRoLEMoN 329,271

= COMBUSTION CHAMBER Filed March 20, 1940 3 Sheets-Sheet 5 Zhwentor r y Gttorneg Patented Sept. 14, 1943 OOMBUSTION CHAMBER Earl W. Jorolemon, Rochester, N. Y., assigner to l General Motors Corporation, Detroit, Mich. a corporation of Delaware Application March 2o, 1940, semina. 324,907

' (ci. -15s-1) l y 6 Claims. This invention relates generally to domestic boilers and furnacesA which are adapted for use with fluid fuel burners and more particularly to improvements in the construction of the combustion chambers thereof for use with conventional gun or prsure atomizing types ofburners.

The principal object of the invention is t Drovide a combustion chamberl construction which will afford both a highly eiilcient combustion of the liquid fuel and a highly emcient transfer of heat to the heat-absorbing surfaces of the boiler or furnace.

One of the principal features of the 'invention v is the constmctionof the combustion chamber, which is preferably of relatively thin sheet metal,

as a substantially closed chamber to provide a relatively confined space in which practically complete combustion occurs before the combustion gases escape through a relatively restricted outlet into the combustion space or primary heating chamber of the boiler or furnace with the heat-absorbing walls thereof primarily heated directly by radiant heat from the combustion chamber.

A further feature-of the invention resides in 'practically complete combustion within the chamber and cause the ameand combustion gases to contact all walls of the combustion chamber to heat the same to maximum temperature almost immediately when the burner is started.

Other objects and features of the invention. such as the location and mounting of the combustion chamber in the boiler or furnace and the novel arrangement, construction'and combina.

tion of parts together with the advantages thereof, will be apparent from, or specically pointed out in the following description and accompanying drawings in which:

Fig. 1 is a vertical sectional view, with parts in elevation, of a furnace embodying my improved combustion chamber.

Fig. 2 is a fragmentary enlarged transverse sectional view taken substantially on line 2-2 -of Fig. 1.

Fig. 3 is a fragmentary enlarged perspective view of the burner end of the combustion chamber of Fig. 1.

Figs. 4 and Stare fragmentary enlarged lsectional views of the connection of the target or baille plate to the combustion chamber taken 'respectively on lines 44-4 and 5-5 of Fig. 2.

Fig. 6 is a fragmentary vertical sectional view. with parts in elevation. ofa boiler .embodying a modified form of combustion chamber.

Flg.'1 is an enlarged `transverse sectional view of the combustion chamber of Fig. 6 taken substantially on line l-'I of Fig. 6. g

Fig. 8 is a fragmentary enlarged vertical sectional view similar to Fig. 6 of a portion of the combustion chamber and adjacent parts.

Fig. 9 is a fragmentaryvertical sectional view,

with parts in elevation, of a boiler of greater capacity than the boiler of Fig. 6 with a further modified form of combustion chamber.

Fig. 10 is an enlarged transverse sectional viewof the' combustion chamber of Fig. 9 taken substantially on line I0- |0 of Fig. 9.

Referring ilrst to theform ofthe invention illustrated in Figs. 1 to 4, there has been shown rather diagrammatically in Fig. 1, a portion of an air heating and conditioning unit such as is disclosed in my Patent No. 2,160,269, granted May 30, 1939, but it will be obvious that my improved combustion chamber may be used with various other types-of air heating units or furnaces and as is necessary for an understanding thereof.

' The combustion space or primary heating chamits passage through the compartment i by conber of the furnace is formed by the sheet metal combustion shell] which may be supported as by spaced brackets 4 within a compartment vl, in spaced relation to the walls of such compartment. The compartment 6 is providedadiacent its lower. end with an air inlet opening 8 and adjacent its upper end with a hot air outlet opening I0 winch is adapted to be connected to the usual air distributingducts. It will be understood that .the air inlet opening l may be associated, if desired, withvan air circulating blower connected to return'air ducts to provide for a positive circulation of the air to be heated during tact with both the heated walls ofthe shell 2 and the walls 'of such other ilue passages as may be provided between Loutlets such as l2 inV the shell 2 and the exhaust stack il.

One of the walls of the combustion shell 2, such as the front wall I6, is provided with a relatively large opening which is adapted to be closed by the cover or burner mounting plate Il secured to the sneu es by bolts 2n. The coveror piste la :s provided with a suitable opening to receive the burner `tube 22 of the oil burner 24 which may be located within a Vcoi'npartrnent 26 and secured to such plate I6 as by bolts 26. The oil burner 24 has not been shown in detail but it will be understood that the same is generally of the pressure yatomizing type in which liquid fluidk is discharged vunder. pressure through an atomizing nozzle in the burner tube 22 and adapted to mix with air supplied through such tube to form the combustible mixture. l

The fuel mixture issuing from the burner nozzle and tube 22 is projected into the sheet metal combustion chamberindicated generally at 20 in which practically complete combustion occurs before the combustion gases escape into the combustion shell 2. ',Ihis chamber 30 is madeof relatively thin sheet metal of such material as certain chrome steel alloys which have been found to withstand the hightemperatures encountered vand attain al maximum temperature and become practically incandescent almost immediately. upon starting the burner to transmit radiant heat directly to the Walls of the combustion shell'2 from which the heat-is eiiiciently absorbed by the kair being circulated over such shell.

The combustion chamber 30' shown in Figs. 1 to 4 may be readily constructed with substantially conical end portions 62 and 34 which are welded to an intermediate cylindrical portion 36. The front end portion 32 is formed with a central opening to receive and t around the burner tube 22 and is provided at this opening with spaced, projecting tongues 38 which, as indicated in Fig. 3, are adapted to be bent outwardly and clamped with a suitable gasket 40 between the ange42 on the burner tube2 2 and the mounting plate i8 as shown in Fig. 1. The rear end portion 34 is closed except for anoutlet opening 44 adjacent the upper portion thereof through which the combustion gases escape into the combustion shell 2. Y

A transverse, sheet metal target and baille plate 46 is provided within the combustion chamber 30 intermediate the ends" thereof but preferably closer to the rear end than to the front end as shown in Fig. 1 This plate 46 is directly in the path of the fuel mixture from they burner and substantially divides the combustion chamber into two compartments .which communicate through the side spaces 46 and bottom space 50 provided between plate 46 and the wall of the cylindrical chamber portion 36. The plate 46 is also preferably made' of special heat-resisting chrome steel '5 to withstand the intense heat to which the same is subjected and to stiifen the plate against permanent distortion due to repeated expansion and contraction on heating and cooling, it is preferably formed with a plurality of corrugations such as the circular corrugations shown in Figs. 1 and 2. The plate 46 may be secured Awithin the chamber portion 36 by means such as the spaced upper angle members 62 and spaced lower angle members 54 which are welded to Iboth the chamber portion and the plate. As shown in detail in Figs. 4 and 5, thelower members 54 areV preferably yformed on a larger radius than the upper members 52 whereby such lower members can more readily bend to some extent to provide, in effect, a flexible connection for the plate 46 which will permit the expansion and contraction thereof without bucklingsuch as might occur if the platewere rigidly fixed to the combustion chain` ber.

bustion chamber 30 is secured between the burner and mountingy plate Il and the chamber is adapted to 'be supportedadjacent its rear endy within the shell 2 in spaced relation thereto as by means of the transversely spaced angle brackets 66. These brackets do not have to be secured to both the chamber I0 and `shell2 but may, for ease Vof assembly and to permit slight relative movement, be welded only to the shell 2 f bent outwardly and the burner 24 secured to the s l mounting plate I6 and this assembly then bolted to the shell 2. the chamber so that the outlet opening `44 will be at the upper side thereof, the front-portion 62 may be formed with a verticallyextending lug 66 which is adapted tot within a longitudinal slot 60 inthe mounting plate i6. v v 4 As has been stated heretofore, the" chamber 30 provides va relatively'lconfined space lin .which practically completecombustion `occurs before the combustion gases or` products of combustion escape' through the relatively restricted outlet 44 into the shell 2. However, it is preferable that the relative dimensions of the chamber 30, the location and ,dimensions of the target and baille plate 46, and the dimensions of the outlet 44 be such that this'desirable result is attained without any appreciable resistance to the escape of the combustion gases or the development of any appreciable combustion pressure within the chamber 30.

The plate 46 has been referred to as a target and baille plate. As will be apparent, such plate is positioned, in part, directly in the path of the fuel mixture from the burner to function as a target and not only thereby provide for increased turbulence of the burning mixture but also attain an extremely high temperature and completely vaporize any unatomized oil from the burner nozzle. The plate 46 also functions as a baille to prevent the burner flame from passing directly to the outlet 44 and by thus increasing the length of flame travel within the chamber' 30, it tends to retain the burner flame in the chamber 30 and provide forsubstantially complete combustion of the fuel mixture therein. In actual practice it has been found that very little, if any, flame ever issues from the outlet 44 and the entire chamber 30 reaches a state of incandescence and maximum temperature and efficiency within a` period of less thantwo minutes from the time when the burner As noted hercabove, the front end of the com-A `is started from a cold condition.

As has been mentioned, the combustion shell 2 Fwill, therefore, be primarily heated by direct radiation from the chamber 30. The shell 2 is also, of course, heated to some extent by the combustion gases escaping from the chamber '30 `into the combustion space provided by the shell To provide for the positioning ofA construction consists generally of the front, in-

termediate, and rear hollow sections, 84 and 88, respectively, within the insulated casing .or jacket 88 with suchboiler sections so yformed as to provide a combustion space 18 which is substantially surrounded by intercommunicating g water spaces in the boiler sections. combustion space 18, the boiler sections are so formed as to provide vertically extending flue spaces 12 between, the sections for passage of combustion gases from the combustion space to the usual exhaust stack. y

The combustion chamber of Figs. 6 to 8, indicated generally at 14, is constructed withthe substantially conical end portions 16 and 18 welded to the intermediate cylindrical -portion 88. The front end portion 16 is provided, asin the formv of Figs. 1 to 5, with a centralopening to receive and nt around the burner tube 82, with tongues Y84 clamped betweenv the burner tube lilange 86` and the burner mounting plate y88 to which the burner is secured as by bolts 98, and with the vertical positioning Alug 82.

The 'front boiler section 62 isprovided with the relatively large opening 84 `which is adapted to be substantially closed by the burner mounting plate 88 bolted tothe front face of section 62. The burner mounting plate 88 is spaced slightly from the upper side of 'the burner tube 82 to provide an arcuate opening 86 to admit air to the combustion space and a baille plate 98 is secured as by bolts |88 to plate 88 and interposed between the combustion chamber 14 and the plate 88 to prevent excessive heat radiation to the latter. This baille plate 88 is spaced as shown at |82 from the burner mounting plate 88 substantially throughout its circumference by sev, eral spacing ribs such as |84 whereby a Vsmall amountof air will be drawn into the combustion space through the opening 98 andthrough the space between the baille plate and burner mounting plateto prevent the transmission of excessive heat to the mounting plate.

The rear end portion 18 of combustion cham- Above 'the` ber 14 is elongated vertically in generally elliptical form so that `the same extends above the top of the cylindrical portion 88 as shown in Figs. 6 and 7. To prevent the direct exhaust of combustion gases from the combustion chamber to the closely adjacent water containing space of the rear boiler section 86 such as might cause excessive sooting, the rear end portion18 is not provided with an exhaust opening such as in the formof Figs. 1 to 5 but the combustion gases escape only through the opening formed by the space between the rear portion 18 and.

[3 sive warping and space this portion from "the boiler.

In the combustion chamber construction oi Figs. 6 to 8, a combined target andbafileplate |88 is provided of substantially they same form yand for the same purposes as the plate y'48 inl Figs. 1 to 5. The plate |88 is, howevenfsho'wn as inclined to some extent because of thelix'nited space available to position theportion" thereof which is Vdirectly in line with the oil vburner nozzle and burner tube 82 at such minimum distance therefrom as has been found tor be most satisfactory. This plate'i88 is corrugated similar to plate 46 but is so form'edasshown par ticularly in Fig. 7, as to"pr ovide only a'lower space indicated at ||8 between theplate' and combustion chamberQ The plate |88 is also secured to thel combustion chamber in .a slightly 'different 4rnalnner than the plate 4.6 in the form vof Figs. 1 'to 5. Adjacentonly the upper part of the plate |88, angle members i2 are secured as r`bygvvelding to both the plate 'and combustion chamber and a cross brace ||4r is provided with' its, bent ends welded vto the chamber and weldedonlyclosely adjacent its ends to the plate |88 so'as to permit theexpansion and contraction of the center and lower edge of the plate on changes of tempera-- ture.

Referring now to Figs. 9`and 10`which show a further modification of the combustionchamber for a boiler yof greater capacity rthany the boiler' of Fig. 6, it will be noted that the boiler construction, insofarr as is' merely generally shown, is the same as that of Fig. 6 heretofore described except that a secondi, intermediate boiler section has been provided. The front endy To provide for the proper distribution and subf stantial equalization of the flow of combustion gases from the combustion chamber ||8 to they flue spaces between the several boiler sections sho'wn in Fig. 9, the intermediate cylindrical portion ||8 of chamber H8 is slightly longer than the corresponding portion of the chamber for the boiler of Fig. 6, and the rear end portion I 281s not only extended above the intermediate portion to provide an exhaust opening to direct .combustion gases forwardly over the chamber as in the form of Figs.'6 to 8 but is further provided with the additional exhaust opening |22 adjacent the upper end thereof to permit some of the combustion `gases to escape rearwardly and upwardly.

The combined target and baille plate |24 issecured to the combustion chamber IIB kin` the same manner as heretofore described with reference to plate |88 of Figs. 6 to 8, but as shown particularly in Fig. 10, this plate |24 is provided with spiral corrugations which provide slightly less resistance to expansion and contraction than the circular, concentric corrugations in the prior forms. It will of course be understood that spiral corrugations could be used, if desired, in the forms of Figs. 1 to 8.

. It will be apparent that many changes and modifications may be made in the detailed construction and arrangement of parts within the i scope of my invention and that many advantages of the several novel features thereof in c addition to those mentioned herein will be obvious to those skilled inthe art. Y I claim: s

. 1. In a heating apparatus, a heat exchange unit having walls defining a hollow combustion space. a combustion chamber within said space in spaced lrelation to the walls thereof, said chamber having an inlety opening adjacent the front end thereof, a liquid fuel burner associated with said inlet secured to one of said walls, a combustionI chamber having an inlet opening for said burner, and means for securing said chambergin said combustion space including means on said chamber adapted to be clamped between said burner and said mounting plate. o.

4. In a heating apparatus, a heat exchange unit j having walls defining a hollow combustion space.

opening to project a fuel mixture throughy said Y opening into said chamber, land said chamber having an'outlet opening adjacent; the rear end thereof with the portion of said chamber adjacent said outlet opening so formed as to direct the combustion Agases upwardly and forwardly over said chamber into said space.

2. In a heating apparatus, a heat exchange unit having walls defining a hollow combustion space.

a combustion chamber within said space having an inlet opening adjacent. the front end thereof, Va liquid fuel burner associated with said inlet opening to project a fuel mixture through said opening intovsaid chamber, said chamber having an outlet opening adjacent the upper portionof the rear end thereof to permit the escape of combustionV gases rearwardly and upwardly into said combustion space,l and said Vchamber having a Vsecond outlet opening adjacent the rear end Y a liquid fuel burner, a burner mounting plate, a

combustion chamber within said space having an inlet opening adjacentr its front end, said burner being associated with said inlet opening to project a fuel mixture through said opening into A`said chamber and a baffle plateinterposed between the front end of said combustion chamber and said burner mounting plate to prevent excessive heat radiation to the latter from said chamber.

'5. 'I'he combination set forth in claim 4, in

which said baille plate is spaced from said burner mounting plate and means `is provided for the admission of air from outside of said combustion space between said plates.

6. In a heating apparatus, a heat exchange unit having walls defining a hollow combustion space,

' a sheet metal combustion .chamber within said space in spaced relation to the walls thereof, said chamber having a fuel inlet, adjacent one end and an outlet adjacent the oppositeend thereofopening into said space,'a liquid fuel burner associated with said inlet to project a fuel mixture i acrosssaid chamber, and a sheet metal baille in saidcombustion chamber extending across the line of projection of the fuel mixture to deflect the flow thereof between said inlet and said outlet and to prevent the passage of unburned liquid to said combustion space.

Y EARL W. J OROLEMON. 

